In manufacturing an electronic device (e.g., a semiconductor device), plasma etching is used in order to transfer a pattern of a mask to a layer to be etched. For example, there is a case where a hard mask is obtained by transferring a pattern of a resist mask to a Si-containing anti-reflection film, and plasma etching is used to transfer the pattern of the hard mask to an organic film.
A plasma etching of an organic film is disclosed in, for example, Japanese Patent Laid-Open Publication No. 2003-168676. In the plasma etching disclosed in the publication, plasma of a processing gas containing hydrogen gas and nitrogen gas is generated within a processing container of a plasma processing apparatus so that the organic film is etched. Specifically, carbon forming the organic film turn into cyan molecules CN by a reaction with active species of nitrogen that are obtained from the nitrogen gas, and the cyan molecules turn into a highly volatile reaction product HCN by a reaction with active species of hydrogen. In the plasma etching disclosed in the publication, the reaction product is volatilized so that the organic film is etched while suppressing reattachment of the reaction product to a workpiece.